sys/kern/sys_process.c

   1 /*-
   2  * Copyright (c) 1994, Sean Eric Fagan
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by Sean Eric Fagan.
  16  * 4. The name of the author may not be used to endorse or promote products
  17  *    derived from this software without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32 #include <sys/cdefs.h>
  33 __FBSDID("$FreeBSD$");
  34
  35 #include "opt_compat.h"
  36
  37 #include <sys/param.h>
  38 #include <sys/systm.h>
  39 #include <sys/lock.h>
  40 #include <sys/mutex.h>
  41 #include <sys/syscallsubr.h>
  42 #include <sys/sysent.h>
  43 #include <sys/sysproto.h>
  44 #include <sys/priv.h>
  45 #include <sys/proc.h>
  46 #include <sys/vnode.h>
  47 #include <sys/ptrace.h>
  48 #include <sys/rwlock.h>
  49 #include <sys/sx.h>
  50 #include <sys/malloc.h>
  51 #include <sys/signalvar.h>
  52
  53 #include <machine/reg.h>
  54
  55 #include <security/audit/audit.h>
  56
  57 #include <vm/vm.h>
  58 #include <vm/pmap.h>
  59 #include <vm/vm_extern.h>
  60 #include <vm/vm_map.h>
  61 #include <vm/vm_kern.h>
  62 #include <vm/vm_object.h>
  63 #include <vm/vm_page.h>
  64 #include <vm/vm_param.h>
  65
  66 #ifdef COMPAT_FREEBSD32
  67 #include <sys/procfs.h>
  68 #include <compat/freebsd32/freebsd32_signal.h>
  69
  70 struct ptrace_io_desc32 {
  71         int             piod_op;
  72         uint32_t        piod_offs;
  73         uint32_t        piod_addr;
  74         uint32_t        piod_len;
  75 };
  76
  77 struct ptrace_vm_entry32 {
  78         int             pve_entry;
  79         int             pve_timestamp;
  80         uint32_t        pve_start;
  81         uint32_t        pve_end;
  82         uint32_t        pve_offset;
  83         u_int           pve_prot;
  84         u_int           pve_pathlen;
  85         int32_t         pve_fileid;
  86         u_int           pve_fsid;
  87         uint32_t        pve_path;
  88 };
  89
  90 struct ptrace_lwpinfo32 {
  91         lwpid_t pl_lwpid;       /* LWP described. */
  92         int     pl_event;       /* Event that stopped the LWP. */
  93         int     pl_flags;       /* LWP flags. */
  94         sigset_t        pl_sigmask;     /* LWP signal mask */
  95         sigset_t        pl_siglist;     /* LWP pending signal */
  96         struct siginfo32 pl_siginfo;    /* siginfo for signal */
  97         char    pl_tdname[MAXCOMLEN + 1];       /* LWP name. */
  98         int     pl_child_pid;           /* New child pid */
  99 };
 100
 101 #endif
 102
 103 /*
 104  * Functions implemented using PROC_ACTION():
 105  *
 106  * proc_read_regs(proc, regs)
 107  *      Get the current user-visible register set from the process
 108  *      and copy it into the regs structure (<machine/reg.h>).
 109  *      The process is stopped at the time read_regs is called.
 110  *
 111  * proc_write_regs(proc, regs)
 112  *      Update the current register set from the passed in regs
 113  *      structure.  Take care to avoid clobbering special CPU
 114  *      registers or privileged bits in the PSL.
 115  *      Depending on the architecture this may have fix-up work to do,
 116  *      especially if the IAR or PCW are modified.
 117  *      The process is stopped at the time write_regs is called.
 118  *
 119  * proc_read_fpregs, proc_write_fpregs
 120  *      deal with the floating point register set, otherwise as above.
 121  *
 122  * proc_read_dbregs, proc_write_dbregs
 123  *      deal with the processor debug register set, otherwise as above.
 124  *
 125  * proc_sstep(proc)
 126  *      Arrange for the process to trap after executing a single instruction.
 127  */
 128
 129 #define PROC_ACTION(action) do {                                        \
 130         int error;                                                      \
 131                                                                         \
 132         PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);                        \
 133         if ((td->td_proc->p_flag & P_INMEM) == 0)                       \
 134                 error = EIO;                                            \
 135         else                                                            \
 136                 error = (action);                                       \
 137         return (error);                                                 \
 138 } while(0)
 139
 140 int
 141 proc_read_regs(struct thread *td, struct reg *regs)
 142 {
 143
 144         PROC_ACTION(fill_regs(td, regs));
 145 }
 146
 147 int
 148 proc_write_regs(struct thread *td, struct reg *regs)
 149 {
 150
 151         PROC_ACTION(set_regs(td, regs));
 152 }
 153
 154 int
 155 proc_read_dbregs(struct thread *td, struct dbreg *dbregs)
 156 {
 157
 158         PROC_ACTION(fill_dbregs(td, dbregs));
 159 }
 160
 161 int
 162 proc_write_dbregs(struct thread *td, struct dbreg *dbregs)
 163 {
 164
 165         PROC_ACTION(set_dbregs(td, dbregs));
 166 }
 167
 168 /*
 169  * Ptrace doesn't support fpregs at all, and there are no security holes
 170  * or translations for fpregs, so we can just copy them.
 171  */
 172 int
 173 proc_read_fpregs(struct thread *td, struct fpreg *fpregs)
 174 {
 175
 176         PROC_ACTION(fill_fpregs(td, fpregs));
 177 }
 178
 179 int
 180 proc_write_fpregs(struct thread *td, struct fpreg *fpregs)
 181 {
 182
 183         PROC_ACTION(set_fpregs(td, fpregs));
 184 }
 185
 186 #ifdef COMPAT_FREEBSD32
 187 /* For 32 bit binaries, we need to expose the 32 bit regs layouts. */
 188 int
 189 proc_read_regs32(struct thread *td, struct reg32 *regs32)
 190 {
 191
 192         PROC_ACTION(fill_regs32(td, regs32));
 193 }
 194
 195 int
 196 proc_write_regs32(struct thread *td, struct reg32 *regs32)
 197 {
 198
 199         PROC_ACTION(set_regs32(td, regs32));
 200 }
 201
 202 int
 203 proc_read_dbregs32(struct thread *td, struct dbreg32 *dbregs32)
 204 {
 205
 206         PROC_ACTION(fill_dbregs32(td, dbregs32));
 207 }
 208
 209 int
 210 proc_write_dbregs32(struct thread *td, struct dbreg32 *dbregs32)
 211 {
 212
 213         PROC_ACTION(set_dbregs32(td, dbregs32));
 214 }
 215
 216 int
 217 proc_read_fpregs32(struct thread *td, struct fpreg32 *fpregs32)
 218 {
 219
 220         PROC_ACTION(fill_fpregs32(td, fpregs32));
 221 }
 222
 223 int
 224 proc_write_fpregs32(struct thread *td, struct fpreg32 *fpregs32)
 225 {
 226
 227         PROC_ACTION(set_fpregs32(td, fpregs32));
 228 }
 229 #endif
 230
 231 int
 232 proc_sstep(struct thread *td)
 233 {
 234
 235         PROC_ACTION(ptrace_single_step(td));
 236 }
 237
 238 int
 239 proc_rwmem(struct proc *p, struct uio *uio)
 240 {
 241         vm_map_t map;
 242         vm_offset_t pageno;             /* page number */
 243         vm_prot_t reqprot;
 244         int error, fault_flags, page_offset, writing;
 245
 246         /*
 247          * Assert that someone has locked this vmspace.  (Should be
 248          * curthread but we can't assert that.)  This keeps the process
 249          * from exiting out from under us until this operation completes.
 250          */
 251         KASSERT(p->p_lock >= 1, ("%s: process %p (pid %d) not held", __func__,
 252             p, p->p_pid));
 253
 254         /*
 255          * The map we want...
 256          */
 257         map = &p->p_vmspace->vm_map;
 258
 259         /*
 260          * If we are writing, then we request vm_fault() to create a private
 261          * copy of each page.  Since these copies will not be writeable by the
 262          * process, we must explicity request that they be dirtied.
 263          */
 264         writing = uio->uio_rw == UIO_WRITE;
 265         reqprot = writing ? VM_PROT_COPY | VM_PROT_READ : VM_PROT_READ;
 266         fault_flags = writing ? VM_FAULT_DIRTY : VM_FAULT_NORMAL;
 267
 268         /*
 269          * Only map in one page at a time.  We don't have to, but it
 270          * makes things easier.  This way is trivial - right?
 271          */
 272         do {
 273                 vm_offset_t uva;
 274                 u_int len;
 275                 vm_page_t m;
 276
 277                 uva = (vm_offset_t)uio->uio_offset;
 278
 279                 /*
 280                  * Get the page number of this segment.
 281                  */
 282                 pageno = trunc_page(uva);
 283                 page_offset = uva - pageno;
 284
 285                 /*
 286                  * How many bytes to copy
 287                  */
 288                 len = min(PAGE_SIZE - page_offset, uio->uio_resid);
 289
 290                 /*
 291                  * Fault and hold the page on behalf of the process.
 292                  */
 293                 error = vm_fault_hold(map, pageno, reqprot, fault_flags, &m);
 294                 if (error != KERN_SUCCESS) {
 295                         if (error == KERN_RESOURCE_SHORTAGE)
 296                                 error = ENOMEM;
 297                         else
 298                                 error = EFAULT;
 299                         break;
 300                 }
 301
 302                 /*
 303                  * Now do the i/o move.
 304                  */
 305                 error = uiomove_fromphys(&m, page_offset, len, uio);
 306
 307                 /* Make the I-cache coherent for breakpoints. */
 308                 if (writing && error == 0) {
 309                         vm_map_lock_read(map);
 310                         if (vm_map_check_protection(map, pageno, pageno +
 311                             PAGE_SIZE, VM_PROT_EXECUTE))
 312                                 vm_sync_icache(map, uva, len);
 313                         vm_map_unlock_read(map);
 314                 }
 315
 316                 /*
 317                  * Release the page.
 318                  */
 319                 vm_page_lock(m);
 320                 vm_page_unhold(m);
 321                 vm_page_unlock(m);
 322
 323         } while (error == 0 && uio->uio_resid > 0);
 324
 325         return (error);
 326 }
 327
 328 static int
 329 ptrace_vm_entry(struct thread *td, struct proc *p, struct ptrace_vm_entry *pve)
 330 {
 331         struct vattr vattr;
 332         vm_map_t map;
 333         vm_map_entry_t entry;
 334         vm_object_t obj, tobj, lobj;
 335         struct vmspace *vm;
 336         struct vnode *vp;
 337         char *freepath, *fullpath;
 338         u_int pathlen;
 339         int error, index;
 340
 341         error = 0;
 342         obj = NULL;
 343
 344         vm = vmspace_acquire_ref(p);
 345         map = &vm->vm_map;
 346         vm_map_lock_read(map);
 347
 348         do {
 349                 entry = map->header.next;
 350                 index = 0;
 351                 while (index < pve->pve_entry && entry != &map->header) {
 352                         entry = entry->next;
 353                         index++;
 354                 }
 355                 if (index != pve->pve_entry) {
 356                         error = EINVAL;
 357                         break;
 358                 }
 359                 while (entry != &map->header &&
 360                     (entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0) {
 361                         entry = entry->next;
 362                         index++;
 363                 }
 364                 if (entry == &map->header) {
 365                         error = ENOENT;
 366                         break;
 367                 }
 368
 369                 /* We got an entry. */
 370                 pve->pve_entry = index + 1;
 371                 pve->pve_timestamp = map->timestamp;
 372                 pve->pve_start = entry->start;
 373                 pve->pve_end = entry->end - 1;
 374                 pve->pve_offset = entry->offset;
 375                 pve->pve_prot = entry->protection;
 376
 377                 /* Backing object's path needed? */
 378                 if (pve->pve_pathlen == 0)
 379                         break;
 380
 381                 pathlen = pve->pve_pathlen;
 382                 pve->pve_pathlen = 0;
 383
 384                 obj = entry->object.vm_object;
 385                 if (obj != NULL)
 386                         VM_OBJECT_RLOCK(obj);
 387         } while (0);
 388
 389         vm_map_unlock_read(map);
 390         vmspace_free(vm);
 391
 392         pve->pve_fsid = VNOVAL;
 393         pve->pve_fileid = VNOVAL;
 394
 395         if (error == 0 && obj != NULL) {
 396                 lobj = obj;
 397                 for (tobj = obj; tobj != NULL; tobj = tobj->backing_object) {
 398                         if (tobj != obj)
 399                                 VM_OBJECT_RLOCK(tobj);
 400                         if (lobj != obj)
 401                                 VM_OBJECT_RUNLOCK(lobj);
 402                         lobj = tobj;
 403                         pve->pve_offset += tobj->backing_object_offset;
 404                 }
 405                 vp = (lobj->type == OBJT_VNODE) ? lobj->handle : NULL;
 406                 if (vp != NULL)
 407                         vref(vp);
 408                 if (lobj != obj)
 409                         VM_OBJECT_RUNLOCK(lobj);
 410                 VM_OBJECT_RUNLOCK(obj);
 411
 412                 if (vp != NULL) {
 413                         freepath = NULL;
 414                         fullpath = NULL;
 415                         vn_fullpath(td, vp, &fullpath, &freepath);
 416                         vn_lock(vp, LK_SHARED | LK_RETRY);
 417                         if (VOP_GETATTR(vp, &vattr, td->td_ucred) == 0) {
 418                                 pve->pve_fileid = vattr.va_fileid;
 419                                 pve->pve_fsid = vattr.va_fsid;
 420                         }
 421                         vput(vp);
 422
 423                         if (fullpath != NULL) {
 424                                 pve->pve_pathlen = strlen(fullpath) + 1;
 425                                 if (pve->pve_pathlen <= pathlen) {
 426                                         error = copyout(fullpath, pve->pve_path,
 427                                             pve->pve_pathlen);
 428                                 } else
 429                                         error = ENAMETOOLONG;
 430                         }
 431                         if (freepath != NULL)
 432                                 free(freepath, M_TEMP);
 433                 }
 434         }
 435         if (error == 0)
 436                 CTR3(KTR_PTRACE, "PT_VM_ENTRY: pid %d, entry %d, start %p",
 437                     p->p_pid, pve->pve_entry, pve->pve_start);
 438
 439         return (error);
 440 }
 441
 442 #ifdef COMPAT_FREEBSD32
 443 static int
 444 ptrace_vm_entry32(struct thread *td, struct proc *p,
 445     struct ptrace_vm_entry32 *pve32)
 446 {
 447         struct ptrace_vm_entry pve;
 448         int error;
 449
 450         pve.pve_entry = pve32->pve_entry;
 451         pve.pve_pathlen = pve32->pve_pathlen;
 452         pve.pve_path = (void *)(uintptr_t)pve32->pve_path;
 453
 454         error = ptrace_vm_entry(td, p, &pve);
 455         if (error == 0) {
 456                 pve32->pve_entry = pve.pve_entry;
 457                 pve32->pve_timestamp = pve.pve_timestamp;
 458                 pve32->pve_start = pve.pve_start;
 459                 pve32->pve_end = pve.pve_end;
 460                 pve32->pve_offset = pve.pve_offset;
 461                 pve32->pve_prot = pve.pve_prot;
 462                 pve32->pve_fileid = pve.pve_fileid;
 463                 pve32->pve_fsid = pve.pve_fsid;
 464         }
 465
 466         pve32->pve_pathlen = pve.pve_pathlen;
 467         return (error);
 468 }
 469
 470 static void
 471 ptrace_lwpinfo_to32(const struct ptrace_lwpinfo *pl,
 472     struct ptrace_lwpinfo32 *pl32)
 473 {
 474
 475         pl32->pl_lwpid = pl->pl_lwpid;
 476         pl32->pl_event = pl->pl_event;
 477         pl32->pl_flags = pl->pl_flags;
 478         pl32->pl_sigmask = pl->pl_sigmask;
 479         pl32->pl_siglist = pl->pl_siglist;
 480         siginfo_to_siginfo32(&pl->pl_siginfo, &pl32->pl_siginfo);
 481         strcpy(pl32->pl_tdname, pl->pl_tdname);
 482         pl32->pl_child_pid = pl->pl_child_pid;
 483 }
 484 #endif /* COMPAT_FREEBSD32 */
 485
 486 /*
 487  * Process debugging system call.
 488  */
 489 #ifndef _SYS_SYSPROTO_H_
 490 struct ptrace_args {
 491         int     req;
 492         pid_t   pid;
 493         caddr_t addr;
 494         int     data;
 495 };
 496 #endif
 497
 498 #ifdef COMPAT_FREEBSD32
 499 /*
 500  * This CPP subterfuge is to try and reduce the number of ifdefs in
 501  * the body of the code.
 502  *   COPYIN(uap->addr, &r.reg, sizeof r.reg);
 503  * becomes either:
 504  *   copyin(uap->addr, &r.reg, sizeof r.reg);
 505  * or
 506  *   copyin(uap->addr, &r.reg32, sizeof r.reg32);
 507  * .. except this is done at runtime.
 508  */
 509 #define COPYIN(u, k, s)         wrap32 ? \
 510         copyin(u, k ## 32, s ## 32) : \
 511         copyin(u, k, s)
 512 #define COPYOUT(k, u, s)        wrap32 ? \
 513         copyout(k ## 32, u, s ## 32) : \
 514         copyout(k, u, s)
 515 #else
 516 #define COPYIN(u, k, s)         copyin(u, k, s)
 517 #define COPYOUT(k, u, s)        copyout(k, u, s)
 518 #endif
 519 int
 520 sys_ptrace(struct thread *td, struct ptrace_args *uap)
 521 {
 522         /*
 523          * XXX this obfuscation is to reduce stack usage, but the register
 524          * structs may be too large to put on the stack anyway.
 525          */
 526         union {
 527                 struct ptrace_io_desc piod;
 528                 struct ptrace_lwpinfo pl;
 529                 struct ptrace_vm_entry pve;
 530                 struct dbreg dbreg;
 531                 struct fpreg fpreg;
 532                 struct reg reg;
 533 #ifdef COMPAT_FREEBSD32
 534                 struct dbreg32 dbreg32;
 535                 struct fpreg32 fpreg32;
 536                 struct reg32 reg32;
 537                 struct ptrace_io_desc32 piod32;
 538                 struct ptrace_lwpinfo32 pl32;
 539                 struct ptrace_vm_entry32 pve32;
 540 #endif
 541         } r;
 542         void *addr;
 543         int error = 0;
 544 #ifdef COMPAT_FREEBSD32
 545         int wrap32 = 0;
 546
 547         if (SV_CURPROC_FLAG(SV_ILP32))
 548                 wrap32 = 1;
 549 #endif
 550         AUDIT_ARG_PID(uap->pid);
 551         AUDIT_ARG_CMD(uap->req);
 552         AUDIT_ARG_VALUE(uap->data);
 553         addr = &r;
 554         switch (uap->req) {
 555         case PT_GETREGS:
 556         case PT_GETFPREGS:
 557         case PT_GETDBREGS:
 558         case PT_LWPINFO:
 559                 break;
 560         case PT_SETREGS:
 561                 error = COPYIN(uap->addr, &r.reg, sizeof r.reg);
 562                 break;
 563         case PT_SETFPREGS:
 564                 error = COPYIN(uap->addr, &r.fpreg, sizeof r.fpreg);
 565                 break;
 566         case PT_SETDBREGS:
 567                 error = COPYIN(uap->addr, &r.dbreg, sizeof r.dbreg);
 568                 break;
 569         case PT_IO:
 570                 error = COPYIN(uap->addr, &r.piod, sizeof r.piod);
 571                 break;
 572         case PT_VM_ENTRY:
 573                 error = COPYIN(uap->addr, &r.pve, sizeof r.pve);
 574                 break;
 575         default:
 576                 addr = uap->addr;
 577                 break;
 578         }
 579         if (error)
 580                 return (error);
 581
 582         error = kern_ptrace(td, uap->req, uap->pid, addr, uap->data);
 583         if (error)
 584                 return (error);
 585
 586         switch (uap->req) {
 587         case PT_VM_ENTRY:
 588                 error = COPYOUT(&r.pve, uap->addr, sizeof r.pve);
 589                 break;
 590         case PT_IO:
 591                 error = COPYOUT(&r.piod, uap->addr, sizeof r.piod);
 592                 break;
 593         case PT_GETREGS:
 594                 error = COPYOUT(&r.reg, uap->addr, sizeof r.reg);
 595                 break;
 596         case PT_GETFPREGS:
 597                 error = COPYOUT(&r.fpreg, uap->addr, sizeof r.fpreg);
 598                 break;
 599         case PT_GETDBREGS:
 600                 error = COPYOUT(&r.dbreg, uap->addr, sizeof r.dbreg);
 601                 break;
 602         case PT_LWPINFO:
 603                 error = copyout(&r.pl, uap->addr, uap->data);
 604                 break;
 605         }
 606
 607         return (error);
 608 }
 609 #undef COPYIN
 610 #undef COPYOUT
 611
 612 #ifdef COMPAT_FREEBSD32
 613 /*
 614  *   PROC_READ(regs, td2, addr);
 615  * becomes either:
 616  *   proc_read_regs(td2, addr);
 617  * or
 618  *   proc_read_regs32(td2, addr);
 619  * .. except this is done at runtime.  There is an additional
 620  * complication in that PROC_WRITE disallows 32 bit consumers
 621  * from writing to 64 bit address space targets.
 622  */
 623 #define PROC_READ(w, t, a)      wrap32 ? \
 624         proc_read_ ## w ## 32(t, a) : \
 625         proc_read_ ## w (t, a)
 626 #define PROC_WRITE(w, t, a)     wrap32 ? \
 627         (safe ? proc_write_ ## w ## 32(t, a) : EINVAL ) : \
 628         proc_write_ ## w (t, a)
 629 #else
 630 #define PROC_READ(w, t, a)      proc_read_ ## w (t, a)
 631 #define PROC_WRITE(w, t, a)     proc_write_ ## w (t, a)
 632 #endif
 633
 634 int
 635 kern_ptrace(struct thread *td, int req, pid_t pid, void *addr, int data)
 636 {
 637         struct iovec iov;
 638         struct uio uio;
 639         struct proc *curp, *p, *pp;
 640         struct thread *td2 = NULL, *td3;
 641         struct ptrace_io_desc *piod = NULL;
 642         struct ptrace_lwpinfo *pl;
 643         int error, write, tmp, num;
 644         int proctree_locked = 0;
 645         lwpid_t tid = 0, *buf;
 646 #ifdef COMPAT_FREEBSD32
 647         int wrap32 = 0, safe = 0;
 648         struct ptrace_io_desc32 *piod32 = NULL;
 649         struct ptrace_lwpinfo32 *pl32 = NULL;
 650         struct ptrace_lwpinfo plr;
 651 #endif
 652
 653         curp = td->td_proc;
 654
 655         /* Lock proctree before locking the process. */
 656         switch (req) {
 657         case PT_TRACE_ME:
 658         case PT_ATTACH:
 659         case PT_STEP:
 660         case PT_CONTINUE:
 661         case PT_TO_SCE:
 662         case PT_TO_SCX:
 663         case PT_SYSCALL:
 664         case PT_FOLLOW_FORK:
 665         case PT_DETACH:
 666                 sx_xlock(&proctree_lock);
 667                 proctree_locked = 1;
 668                 break;
 669         default:
 670                 break;
 671         }
 672
 673         write = 0;
 674         if (req == PT_TRACE_ME) {
 675                 p = td->td_proc;
 676                 PROC_LOCK(p);
 677         } else {
 678                 if (pid <= PID_MAX) {
 679                         if ((p = pfind(pid)) == NULL) {
 680                                 if (proctree_locked)
 681                                         sx_xunlock(&proctree_lock);
 682                                 return (ESRCH);
 683                         }
 684                 } else {
 685                         td2 = tdfind(pid, -1);
 686                         if (td2 == NULL) {
 687                                 if (proctree_locked)
 688                                         sx_xunlock(&proctree_lock);
 689                                 return (ESRCH);
 690                         }
 691                         p = td2->td_proc;
 692                         tid = pid;
 693                         pid = p->p_pid;
 694                 }
 695         }
 696         AUDIT_ARG_PROCESS(p);
 697
 698         if ((p->p_flag & P_WEXIT) != 0) {
 699                 error = ESRCH;
 700                 goto fail;
 701         }
 702         if ((error = p_cansee(td, p)) != 0)
 703                 goto fail;
 704
 705         if ((error = p_candebug(td, p)) != 0)
 706                 goto fail;
 707
 708         /*
 709          * System processes can't be debugged.
 710          */
 711         if ((p->p_flag & P_SYSTEM) != 0) {
 712                 error = EINVAL;
 713                 goto fail;
 714         }
 715
 716         if (tid == 0) {
 717                 if ((p->p_flag & P_STOPPED_TRACE) != 0) {
 718                         KASSERT(p->p_xthread != NULL, ("NULL p_xthread"));
 719                         td2 = p->p_xthread;
 720                 } else {
 721                         td2 = FIRST_THREAD_IN_PROC(p);
 722                 }
 723                 tid = td2->td_tid;
 724         }
 725
 726 #ifdef COMPAT_FREEBSD32
 727         /*
 728          * Test if we're a 32 bit client and what the target is.
 729          * Set the wrap controls accordingly.
 730          */
 731         if (SV_CURPROC_FLAG(SV_ILP32)) {
 732                 if (SV_PROC_FLAG(td2->td_proc, SV_ILP32))
 733                         safe = 1;
 734                 wrap32 = 1;
 735         }
 736 #endif
 737         /*
 738          * Permissions check
 739          */
 740         switch (req) {
 741         case PT_TRACE_ME:
 742                 /* Always legal. */
 743                 break;
 744
 745         case PT_ATTACH:
 746                 /* Self */
 747                 if (p->p_pid == td->td_proc->p_pid) {
 748                         error = EINVAL;
 749                         goto fail;
 750                 }
 751
 752                 /* Already traced */
 753                 if (p->p_flag & P_TRACED) {
 754                         error = EBUSY;
 755                         goto fail;
 756                 }
 757
 758                 /* Can't trace an ancestor if you're being traced. */
 759                 if (curp->p_flag & P_TRACED) {
 760                         for (pp = curp->p_pptr; pp != NULL; pp = pp->p_pptr) {
 761                                 if (pp == p) {
 762                                         error = EINVAL;
 763                                         goto fail;
 764                                 }
 765                         }
 766                 }
 767
 768
 769                 /* OK */
 770                 break;
 771
 772         case PT_CLEARSTEP:
 773                 /* Allow thread to clear single step for itself */
 774                 if (td->td_tid == tid)
 775                         break;
 776
 777                 /* FALLTHROUGH */
 778         default:
 779                 /* not being traced... */
 780                 if ((p->p_flag & P_TRACED) == 0) {
 781                         error = EPERM;
 782                         goto fail;
 783                 }
 784
 785                 /* not being traced by YOU */
 786                 if (p->p_pptr != td->td_proc) {
 787                         error = EBUSY;
 788                         goto fail;
 789                 }
 790
 791                 /* not currently stopped */
 792                 if ((p->p_flag & (P_STOPPED_SIG | P_STOPPED_TRACE)) == 0 ||
 793                     p->p_suspcount != p->p_numthreads  ||
 794                     (p->p_flag & P_WAITED) == 0) {
 795                         error = EBUSY;
 796                         goto fail;
 797                 }
 798
 799                 if ((p->p_flag & P_STOPPED_TRACE) == 0) {
 800                         static int count = 0;
 801                         if (count++ == 0)
 802                                 printf("P_STOPPED_TRACE not set.\n");
 803                 }
 804
 805                 /* OK */
 806                 break;
 807         }
 808
 809         /* Keep this process around until we finish this request. */
 810         _PHOLD(p);
 811
 812 #ifdef FIX_SSTEP
 813         /*
 814          * Single step fixup ala procfs
 815          */
 816         FIX_SSTEP(td2);
 817 #endif
 818
 819         /*
 820          * Actually do the requests
 821          */
 822
 823         td->td_retval[0] = 0;
 824
 825         switch (req) {
 826         case PT_TRACE_ME:
 827                 /* set my trace flag and "owner" so it can read/write me */
 828                 p->p_flag |= P_TRACED;
 829                 if (p->p_flag & P_PPWAIT)
 830                         p->p_flag |= P_PPTRACE;
 831                 p->p_oppid = p->p_pptr->p_pid;
 832                 CTR1(KTR_PTRACE, "PT_TRACE_ME: pid %d", p->p_pid);
 833                 break;
 834
 835         case PT_ATTACH:
 836                 /* security check done above */
 837                 /*
 838                  * It would be nice if the tracing relationship was separate
 839                  * from the parent relationship but that would require
 840                  * another set of links in the proc struct or for "wait"
 841                  * to scan the entire proc table.  To make life easier,
 842                  * we just re-parent the process we're trying to trace.
 843                  * The old parent is remembered so we can put things back
 844                  * on a "detach".
 845                  */
 846                 p->p_flag |= P_TRACED;
 847                 p->p_oppid = p->p_pptr->p_pid;
 848                 if (p->p_pptr != td->td_proc) {
 849                         proc_reparent(p, td->td_proc);
 850                 }
 851                 data = SIGSTOP;
 852                 CTR2(KTR_PTRACE, "PT_ATTACH: pid %d, oppid %d", p->p_pid,
 853                     p->p_oppid);
 854                 goto sendsig;   /* in PT_CONTINUE below */
 855
 856         case PT_CLEARSTEP:
 857                 CTR2(KTR_PTRACE, "PT_CLEARSTEP: tid %d (pid %d)", td2->td_tid,
 858                     p->p_pid);
 859                 error = ptrace_clear_single_step(td2);
 860                 break;
 861
 862         case PT_SETSTEP:
 863                 CTR2(KTR_PTRACE, "PT_SETSTEP: tid %d (pid %d)", td2->td_tid,
 864                     p->p_pid);
 865                 error = ptrace_single_step(td2);
 866                 break;
 867
 868         case PT_SUSPEND:
 869                 CTR2(KTR_PTRACE, "PT_SUSPEND: tid %d (pid %d)", td2->td_tid,
 870                     p->p_pid);
 871                 td2->td_dbgflags |= TDB_SUSPEND;
 872                 thread_lock(td2);
 873                 td2->td_flags |= TDF_NEEDSUSPCHK;
 874                 thread_unlock(td2);
 875                 break;
 876
 877         case PT_RESUME:
 878                 CTR2(KTR_PTRACE, "PT_RESUME: tid %d (pid %d)", td2->td_tid,
 879                     p->p_pid);
 880                 td2->td_dbgflags &= ~TDB_SUSPEND;
 881                 break;
 882
 883         case PT_FOLLOW_FORK:
 884                 CTR3(KTR_PTRACE, "PT_FOLLOW_FORK: pid %d %s -> %s", p->p_pid,
 885                     p->p_flag & P_FOLLOWFORK ? "enabled" : "disabled",
 886                     data ? "enabled" : "disabled");
 887                 if (data)
 888                         p->p_flag |= P_FOLLOWFORK;
 889                 else
 890                         p->p_flag &= ~P_FOLLOWFORK;
 891                 break;
 892
 893         case PT_STEP:
 894         case PT_CONTINUE:
 895         case PT_TO_SCE:
 896         case PT_TO_SCX:
 897         case PT_SYSCALL:
 898         case PT_DETACH:
 899                 /* Zero means do not send any signal */
 900                 if (data < 0 || data > _SIG_MAXSIG) {
 901                         error = EINVAL;
 902                         break;
 903                 }
 904
 905                 switch (req) {
 906                 case PT_STEP:
 907                         CTR2(KTR_PTRACE, "PT_STEP: tid %d (pid %d)",
 908                             td2->td_tid, p->p_pid);
 909                         error = ptrace_single_step(td2);
 910                         if (error)
 911                                 goto out;
 912                         break;
 913                 case PT_CONTINUE:
 914                 case PT_TO_SCE:
 915                 case PT_TO_SCX:
 916                 case PT_SYSCALL:
 917                         if (addr != (void *)1) {
 918                                 error = ptrace_set_pc(td2,
 919                                     (u_long)(uintfptr_t)addr);
 920                                 if (error)
 921                                         goto out;
 922                         }
 923                         switch (req) {
 924                         case PT_TO_SCE:
 925                                 p->p_stops |= S_PT_SCE;
 926                                 CTR2(KTR_PTRACE,
 927                                     "PT_TO_SCE: pid %d, stops = %#x", p->p_pid,
 928                                     p->p_stops);
 929                                 break;
 930                         case PT_TO_SCX:
 931                                 p->p_stops |= S_PT_SCX;
 932                                 CTR2(KTR_PTRACE,
 933                                     "PT_TO_SCX: pid %d, stops = %#x", p->p_pid,
 934                                     p->p_stops);
 935                                 break;
 936                         case PT_SYSCALL:
 937                                 p->p_stops |= S_PT_SCE | S_PT_SCX;
 938                                 CTR2(KTR_PTRACE,
 939                                     "PT_SYSCALL: pid %d, stops = %#x", p->p_pid,
 940                                     p->p_stops);
 941                                 break;
 942                         case PT_CONTINUE:
 943                                 CTR1(KTR_PTRACE,
 944                                     "PT_CONTINUE: pid %d", p->p_pid);
 945                                 break;
 946                         }
 947                         break;
 948                 case PT_DETACH:
 949                         /* reset process parent */
 950                         if (p->p_oppid != p->p_pptr->p_pid) {
 951                                 PROC_LOCK(p->p_pptr);
 952                                 sigqueue_take(p->p_ksi);
 953                                 PROC_UNLOCK(p->p_pptr);
 954
 955                                 pp = proc_realparent(p);
 956                                 proc_reparent(p, pp);
 957                                 if (pp == initproc)
 958                                         p->p_sigparent = SIGCHLD;
 959                                 CTR2(KTR_PTRACE,
 960                                     "PT_DETACH: pid %d reparented to pid %d",
 961                                     p->p_pid, pp->p_pid);
 962                         } else
 963                                 CTR1(KTR_PTRACE, "PT_DETACH: pid %d", p->p_pid);
 964                         p->p_oppid = 0;
 965                         p->p_flag &= ~(P_TRACED | P_WAITED | P_FOLLOWFORK);
 966                         p->p_stops = 0;
 967
 968                         /* should we send SIGCHLD? */
 969                         /* childproc_continued(p); */
 970                         break;
 971                 }
 972
 973         sendsig:
 974                 if (proctree_locked) {
 975                         sx_xunlock(&proctree_lock);
 976                         proctree_locked = 0;
 977                 }
 978                 p->p_xstat = data;
 979                 p->p_xthread = NULL;
 980                 if ((p->p_flag & (P_STOPPED_SIG | P_STOPPED_TRACE)) != 0) {
 981                         /* deliver or queue signal */
 982                         td2->td_dbgflags &= ~TDB_XSIG;
 983                         td2->td_xsig = data;
 984
 985                         if (req == PT_DETACH) {
 986                                 FOREACH_THREAD_IN_PROC(p, td3)
 987                                         td3->td_dbgflags &= ~TDB_SUSPEND;
 988                         }
 989                         /*
 990                          * unsuspend all threads, to not let a thread run,
 991                          * you should use PT_SUSPEND to suspend it before
 992                          * continuing process.
 993                          */
 994                         PROC_SLOCK(p);
 995                         p->p_flag &= ~(P_STOPPED_TRACE|P_STOPPED_SIG|P_WAITED);
 996                         thread_unsuspend(p);
 997                         PROC_SUNLOCK(p);
 998                         if (req == PT_ATTACH)
 999                                 kern_psignal(p, data);
1000                 } else {
1001                         if (data)
1002                                 kern_psignal(p, data);
1003                 }
1004                 break;
1005
1006         case PT_WRITE_I:
1007         case PT_WRITE_D:
1008                 td2->td_dbgflags |= TDB_USERWR;
1009                 write = 1;
1010                 /* FALLTHROUGH */
1011         case PT_READ_I:
1012         case PT_READ_D:
1013                 PROC_UNLOCK(p);
1014                 tmp = 0;
1015                 /* write = 0 set above */
1016                 iov.iov_base = write ? (caddr_t)&data : (caddr_t)&tmp;
1017                 iov.iov_len = sizeof(int);
1018                 uio.uio_iov = &iov;
1019                 uio.uio_iovcnt = 1;
1020                 uio.uio_offset = (off_t)(uintptr_t)addr;
1021                 uio.uio_resid = sizeof(int);
1022                 uio.uio_segflg = UIO_SYSSPACE;  /* i.e.: the uap */
1023                 uio.uio_rw = write ? UIO_WRITE : UIO_READ;
1024                 uio.uio_td = td;
1025                 error = proc_rwmem(p, &uio);
1026                 if (uio.uio_resid != 0) {
1027                         /*
1028                          * XXX proc_rwmem() doesn't currently return ENOSPC,
1029                          * so I think write() can bogusly return 0.
1030                          * XXX what happens for short writes?  We don't want
1031                          * to write partial data.
1032                          * XXX proc_rwmem() returns EPERM for other invalid
1033                          * addresses.  Convert this to EINVAL.  Does this
1034                          * clobber returns of EPERM for other reasons?
1035                          */
1036                         if (error == 0 || error == ENOSPC || error == EPERM)
1037                                 error = EINVAL; /* EOF */
1038                 }
1039                 if (!write)
1040                         td->td_retval[0] = tmp;
1041                 if (error == 0) {
1042                         if (write)
1043                                 CTR3(KTR_PTRACE, "PT_WRITE: pid %d: %p <= %#x",
1044                                     p->p_pid, addr, data);
1045                         else
1046                                 CTR3(KTR_PTRACE, "PT_READ: pid %d: %p >= %#x",
1047                                     p->p_pid, addr, tmp);
1048                 }
1049                 PROC_LOCK(p);
1050                 break;
1051
1052         case PT_IO:
1053 #ifdef COMPAT_FREEBSD32
1054                 if (wrap32) {
1055                         piod32 = addr;
1056                         iov.iov_base = (void *)(uintptr_t)piod32->piod_addr;
1057                         iov.iov_len = piod32->piod_len;
1058                         uio.uio_offset = (off_t)(uintptr_t)piod32->piod_offs;
1059                         uio.uio_resid = piod32->piod_len;
1060                 } else
1061 #endif
1062                 {
1063                         piod = addr;
1064                         iov.iov_base = piod->piod_addr;
1065                         iov.iov_len = piod->piod_len;
1066                         uio.uio_offset = (off_t)(uintptr_t)piod->piod_offs;
1067                         uio.uio_resid = piod->piod_len;
1068                 }
1069                 uio.uio_iov = &iov;
1070                 uio.uio_iovcnt = 1;
1071                 uio.uio_segflg = UIO_USERSPACE;
1072                 uio.uio_td = td;
1073 #ifdef COMPAT_FREEBSD32
1074                 tmp = wrap32 ? piod32->piod_op : piod->piod_op;
1075 #else
1076                 tmp = piod->piod_op;
1077 #endif
1078                 switch (tmp) {
1079                 case PIOD_READ_D:
1080                 case PIOD_READ_I:
1081                         CTR3(KTR_PTRACE, "PT_IO: pid %d: READ (%p, %#x)",
1082                             p->p_pid, (uintptr_t)uio.uio_offset, uio.uio_resid);
1083                         uio.uio_rw = UIO_READ;
1084                         break;
1085                 case PIOD_WRITE_D:
1086                 case PIOD_WRITE_I:
1087                         CTR3(KTR_PTRACE, "PT_IO: pid %d: WRITE (%p, %#x)",
1088                             p->p_pid, (uintptr_t)uio.uio_offset, uio.uio_resid);
1089                         td2->td_dbgflags |= TDB_USERWR;
1090                         uio.uio_rw = UIO_WRITE;
1091                         break;
1092                 default:
1093                         error = EINVAL;
1094                         goto out;
1095                 }
1096                 PROC_UNLOCK(p);
1097                 error = proc_rwmem(p, &uio);
1098 #ifdef COMPAT_FREEBSD32
1099                 if (wrap32)
1100                         piod32->piod_len -= uio.uio_resid;
1101                 else
1102 #endif
1103                         piod->piod_len -= uio.uio_resid;
1104                 PROC_LOCK(p);
1105                 break;
1106
1107         case PT_KILL:
1108                 CTR1(KTR_PTRACE, "PT_KILL: pid %d", p->p_pid);
1109                 data = SIGKILL;
1110                 goto sendsig;   /* in PT_CONTINUE above */
1111
1112         case PT_SETREGS:
1113                 CTR2(KTR_PTRACE, "PT_SETREGS: tid %d (pid %d)", td2->td_tid,
1114                     p->p_pid);
1115                 td2->td_dbgflags |= TDB_USERWR;
1116                 error = PROC_WRITE(regs, td2, addr);
1117                 break;
1118
1119         case PT_GETREGS:
1120                 CTR2(KTR_PTRACE, "PT_GETREGS: tid %d (pid %d)", td2->td_tid,
1121                     p->p_pid);
1122                 error = PROC_READ(regs, td2, addr);
1123                 break;
1124
1125         case PT_SETFPREGS:
1126                 CTR2(KTR_PTRACE, "PT_SETFPREGS: tid %d (pid %d)", td2->td_tid,
1127                     p->p_pid);
1128                 td2->td_dbgflags |= TDB_USERWR;
1129                 error = PROC_WRITE(fpregs, td2, addr);
1130                 break;
1131
1132         case PT_GETFPREGS:
1133                 CTR2(KTR_PTRACE, "PT_GETFPREGS: tid %d (pid %d)", td2->td_tid,
1134                     p->p_pid);
1135                 error = PROC_READ(fpregs, td2, addr);
1136                 break;
1137
1138         case PT_SETDBREGS:
1139                 CTR2(KTR_PTRACE, "PT_SETDBREGS: tid %d (pid %d)", td2->td_tid,
1140                     p->p_pid);
1141                 td2->td_dbgflags |= TDB_USERWR;
1142                 error = PROC_WRITE(dbregs, td2, addr);
1143                 break;
1144
1145         case PT_GETDBREGS:
1146                 CTR2(KTR_PTRACE, "PT_GETDBREGS: tid %d (pid %d)", td2->td_tid,
1147                     p->p_pid);
1148                 error = PROC_READ(dbregs, td2, addr);
1149                 break;
1150
1151         case PT_LWPINFO:
1152                 if (data <= 0 ||
1153 #ifdef COMPAT_FREEBSD32
1154                     (!wrap32 && data > sizeof(*pl)) ||
1155                     (wrap32 && data > sizeof(*pl32))) {
1156 #else
1157                     data > sizeof(*pl)) {
1158 #endif
1159                         error = EINVAL;
1160                         break;
1161                 }
1162 #ifdef COMPAT_FREEBSD32
1163                 if (wrap32) {
1164                         pl = &plr;
1165                         pl32 = addr;
1166                 } else
1167 #endif
1168                 pl = addr;
1169                 pl->pl_lwpid = td2->td_tid;
1170                 pl->pl_event = PL_EVENT_NONE;
1171                 pl->pl_flags = 0;
1172                 if (td2->td_dbgflags & TDB_XSIG) {
1173                         pl->pl_event = PL_EVENT_SIGNAL;
1174                         if (td2->td_dbgksi.ksi_signo != 0 &&
1175 #ifdef COMPAT_FREEBSD32
1176                             ((!wrap32 && data >= offsetof(struct ptrace_lwpinfo,
1177                             pl_siginfo) + sizeof(pl->pl_siginfo)) ||
1178                             (wrap32 && data >= offsetof(struct ptrace_lwpinfo32,
1179                             pl_siginfo) + sizeof(struct siginfo32)))
1180 #else
1181                             data >= offsetof(struct ptrace_lwpinfo, pl_siginfo)
1182                             + sizeof(pl->pl_siginfo)
1183 #endif
1184                         ){
1185                                 pl->pl_flags |= PL_FLAG_SI;
1186                                 pl->pl_siginfo = td2->td_dbgksi.ksi_info;
1187                         }
1188                 }
1189                 if ((pl->pl_flags & PL_FLAG_SI) == 0)
1190                         bzero(&pl->pl_siginfo, sizeof(pl->pl_siginfo));
1191                 if (td2->td_dbgflags & TDB_SCE)
1192                         pl->pl_flags |= PL_FLAG_SCE;
1193                 else if (td2->td_dbgflags & TDB_SCX)
1194                         pl->pl_flags |= PL_FLAG_SCX;
1195                 if (td2->td_dbgflags & TDB_EXEC)
1196                         pl->pl_flags |= PL_FLAG_EXEC;
1197                 if (td2->td_dbgflags & TDB_FORK) {
1198                         pl->pl_flags |= PL_FLAG_FORKED;
1199                         pl->pl_child_pid = td2->td_dbg_forked;
1200                 }
1201                 if (td2->td_dbgflags & TDB_CHILD)
1202                         pl->pl_flags |= PL_FLAG_CHILD;
1203                 pl->pl_sigmask = td2->td_sigmask;
1204                 pl->pl_siglist = td2->td_siglist;
1205                 strcpy(pl->pl_tdname, td2->td_name);
1206 #ifdef COMPAT_FREEBSD32
1207                 if (wrap32)
1208                         ptrace_lwpinfo_to32(pl, pl32);
1209 #endif
1210                 CTR5(KTR_PTRACE,
1211             "PT_LWPINFO: tid %d (pid %d) event %d flags %#x child pid %d",
1212                     td2->td_tid, p->p_pid, pl->pl_event, pl->pl_flags,
1213                     pl->pl_child_pid);
1214                 break;
1215
1216         case PT_GETNUMLWPS:
1217                 CTR2(KTR_PTRACE, "PT_GETNUMLWPS: pid %d: %d threads", p->p_pid,
1218                     p->p_numthreads);
1219                 td->td_retval[0] = p->p_numthreads;
1220                 break;
1221
1222         case PT_GETLWPLIST:
1223                 CTR3(KTR_PTRACE, "PT_GETLWPLIST: pid %d: data %d, actual %d",
1224                     p->p_pid, data, p->p_numthreads);
1225                 if (data <= 0) {
1226                         error = EINVAL;
1227                         break;
1228                 }
1229                 num = imin(p->p_numthreads, data);
1230                 PROC_UNLOCK(p);
1231                 buf = malloc(num * sizeof(lwpid_t), M_TEMP, M_WAITOK);
1232                 tmp = 0;
1233                 PROC_LOCK(p);
1234                 FOREACH_THREAD_IN_PROC(p, td2) {
1235                         if (tmp >= num)
1236                                 break;
1237                         buf[tmp++] = td2->td_tid;
1238                 }
1239                 PROC_UNLOCK(p);
1240                 error = copyout(buf, addr, tmp * sizeof(lwpid_t));
1241                 free(buf, M_TEMP);
1242                 if (!error)
1243                         td->td_retval[0] = tmp;
1244                 PROC_LOCK(p);
1245                 break;
1246
1247         case PT_VM_TIMESTAMP:
1248                 CTR2(KTR_PTRACE, "PT_VM_TIMESTAMP: pid %d: timestamp %d",
1249                     p->p_pid, p->p_vmspace->vm_map.timestamp);
1250                 td->td_retval[0] = p->p_vmspace->vm_map.timestamp;
1251                 break;
1252
1253         case PT_VM_ENTRY:
1254                 PROC_UNLOCK(p);
1255 #ifdef COMPAT_FREEBSD32
1256                 if (wrap32)
1257                         error = ptrace_vm_entry32(td, p, addr);
1258                 else
1259 #endif
1260                 error = ptrace_vm_entry(td, p, addr);
1261                 PROC_LOCK(p);
1262                 break;
1263
1264         default:
1265 #ifdef __HAVE_PTRACE_MACHDEP
1266                 if (req >= PT_FIRSTMACH) {
1267                         PROC_UNLOCK(p);
1268                         error = cpu_ptrace(td2, req, addr, data);
1269                         PROC_LOCK(p);
1270                 } else
1271 #endif
1272                         /* Unknown request. */
1273                         error = EINVAL;
1274                 break;
1275         }
1276
1277 out:
1278         /* Drop our hold on this process now that the request has completed. */
1279         _PRELE(p);
1280 fail:
1281         PROC_UNLOCK(p);
1282         if (proctree_locked)
1283                 sx_xunlock(&proctree_lock);
1284         return (error);
1285 }
1286 #undef PROC_READ
1287 #undef PROC_WRITE
1288
1289 /*
1290  * Stop a process because of a debugging event;
1291  * stay stopped until p->p_step is cleared
1292  * (cleared by PIOCCONT in procfs).
1293  */
1294 void
1295 stopevent(struct proc *p, unsigned int event, unsigned int val)
1296 {
1297
1298         PROC_LOCK_ASSERT(p, MA_OWNED);
1299         p->p_step = 1;
1300         CTR3(KTR_PTRACE, "stopevent: pid %d event %u val %u", p->p_pid, event,
1301             val);
1302         do {
1303                 p->p_xstat = val;
1304                 p->p_xthread = NULL;
1305                 p->p_stype = event;     /* Which event caused the stop? */
1306                 wakeup(&p->p_stype);    /* Wake up any PIOCWAIT'ing procs */
1307                 msleep(&p->p_step, &p->p_mtx, PWAIT, "stopevent", 0);
1308         } while (p->p_step);
1309 }